[rfa] Build cv-qualified types correctly

[Daniel Jacobowitz <drow at mvista dot com>]

We call make_cv_type mostly on unfinished types.  We then later decide they
are opaque (nfields == 0), and go to look them up.  That's a bug.  We then
look up just the name and discard cv-qualifiers.  That's a bug too.  This
patch fixes both.

Needed for my 3.0/dwarf2 work, no regressions on 2.95.3/stabs/x86-linux. 
Fixes the missing "const" I referenced in a previous message today.

OK to commit?

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

2001-12-06  Daniel Jacobowitz  <drow@mvista.com>

	* gdbtypes.c (finish_cv_type): New function.
	(check_typedef): Remove ``register'' keyword from argument. 
	Preserve const and volatile attributes across filling in
	opaque types.
	* gdbtypes.h (finish_cv_type): Add prototype.

	* hp-symtab-read.c (hpread_read_struct_type): Call finish_cv_type.
	* stabsread.c (read_struct_type): Likewise.
	* dwarf2read.c (read_structure_scope): Likewise.  Remove redundant
	assignment to die->type.

Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.36
diff -u -p -r1.36 dwarf2read.c
--- dwarf2read.c	2001/11/29 13:19:05	1.36
+++ dwarf2read.c	2001/12/06 22:33:17
@@ -2364,7 +2364,7 @@ read_structure_scope (struct die_info *d
       TYPE_FLAGS (type) |= TYPE_FLAG_STUB;
     }
 
-  die->type = type;
+  finish_cv_type (die->type);
 }
 
 /* Given a pointer to a die which begins an enumeration, process all
Index: gdbtypes.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbtypes.c,v
retrieving revision 1.28
diff -u -p -r1.28 gdbtypes.c
--- gdbtypes.c	2001/11/15 01:55:59	1.28
+++ gdbtypes.c	2001/12/06 22:33:17
@@ -36,6 +36,7 @@
 #include "gdbcmd.h"
 #include "wrapper.h"
 #include "cp-abi.h"
+#include "gdb_assert.h"
 
 /* These variables point to the objects
    representing the predefined C data types.  */
@@ -469,9 +470,52 @@ make_cv_type (int cnst, int voltl, struc
   return ntype;
 }
 
+/* When reading in a class type, we may have created references to
+   cv-qualified versions of the type (in method arguments, for
+   instance).  Update everything on the cv ring from the primary
+   type TYPE.
+
+   The only reason we do not need to do the same thing for address
+   spaces is that type readers do not create address space qualified
+   types.  */
+void
+finish_cv_type (struct type *type)
+{
+  struct type *ntype, *cv_type, *ptr_type, *ref_type;
+  int cv_flags;
+
+  gdb_assert (!TYPE_CONST (type) && !TYPE_VOLATILE (type));
+
+  ntype = type;
+  while ((ntype = TYPE_CV_TYPE (ntype)) != type)
+    {
+      /* Save cv_flags.  */
+      cv_flags = TYPE_FLAGS (ntype) & (TYPE_FLAG_VOLATILE | TYPE_FLAG_CONST);
+
+      /* If any reference or pointer types were created, save them too.  */
+      ptr_type = TYPE_POINTER_TYPE (ntype);
+      ref_type = TYPE_REFERENCE_TYPE (ntype);
+
+      /* Don't disturb the CV chain.  */
+      cv_type = TYPE_CV_TYPE (ntype);
+
+      /* Verify that we haven't added any address-space qualified types,
+	 for the future.  */
+      gdb_assert (ntype == TYPE_AS_TYPE (ntype));
 
+      /* Copy original type */
+      memcpy ((char *) ntype, (char *) type, sizeof (struct type));
 
+      /* Restore everything.  */
+      TYPE_POINTER_TYPE (ntype) = ptr_type;
+      TYPE_REFERENCE_TYPE (ntype) = ref_type;
+      TYPE_CV_TYPE (ntype) = cv_type;
+      TYPE_FLAGS (ntype) = TYPE_FLAGS (ntype) | cv_flags;
 
+      TYPE_AS_TYPE (ntype) = ntype;
+    }
+}
+
 /* Implement direct support for MEMBER_TYPE in GNU C++.
    May need to construct such a type if this is the first use.
    The TYPE is the type of the member.  The DOMAIN is the type
@@ -1144,9 +1188,11 @@ struct complaint stub_noname_complaint =
 {"stub type has NULL name", 0, 0};
 
 struct type *
-check_typedef (register struct type *type)
+check_typedef (struct type *type)
 {
   struct type *orig_type = type;
+  int is_const, is_volatile;
+
   while (TYPE_CODE (type) == TYPE_CODE_TYPEDEF)
     {
       if (!TYPE_TARGET_TYPE (type))
@@ -1179,6 +1225,9 @@ check_typedef (register struct type *typ
       type = TYPE_TARGET_TYPE (type);
     }
 
+  is_const = TYPE_CONST (type);
+  is_volatile = TYPE_VOLATILE (type);
+
   /* If this is a struct/class/union with no fields, then check whether a
      full definition exists somewhere else.  This is for systems where a
      type definition with no fields is issued for such types, instead of
@@ -1195,9 +1244,7 @@ check_typedef (register struct type *typ
 	}
       newtype = lookup_transparent_type (name);
       if (newtype)
-	{
-	  memcpy ((char *) type, (char *) newtype, sizeof (struct type));
-	}
+	make_cv_type (is_const, is_volatile, newtype, &type);
     }
   /* Otherwise, rely on the stub flag being set for opaque/stubbed types */
   else if ((TYPE_FLAGS (type) & TYPE_FLAG_STUB) && !currently_reading_symtab)
@@ -1215,9 +1262,7 @@ check_typedef (register struct type *typ
 	}
       sym = lookup_symbol (name, 0, STRUCT_NAMESPACE, 0, (struct symtab **) NULL);
       if (sym)
-	{
-	  memcpy ((char *) type, (char *) SYMBOL_TYPE (sym), sizeof (struct type));
-	}
+	make_cv_type (is_const, is_volatile, SYMBOL_TYPE (sym), &type);
     }
 
   if (TYPE_FLAGS (type) & TYPE_FLAG_TARGET_STUB)
Index: gdbtypes.h
===================================================================
RCS file: /cvs/src/src/gdb/gdbtypes.h,v
retrieving revision 1.18
diff -u -p -r1.18 gdbtypes.h
--- gdbtypes.h	2001/11/15 01:55:59	1.18
+++ gdbtypes.h	2001/12/06 22:33:18
@@ -1037,6 +1037,8 @@ extern struct type *make_reference_type 
 
 extern struct type *make_cv_type (int, int, struct type *, struct type **);
 
+extern void finish_cv_type (struct type *);
+
 extern int address_space_name_to_int (char *);
 
 extern char *address_space_int_to_name (int);
Index: hp-symtab-read.c
===================================================================
RCS file: /cvs/src/src/gdb/hp-symtab-read.c,v
retrieving revision 1.7
diff -u -p -r1.7 hp-symtab-read.c
--- hp-symtab-read.c	2001/05/12 03:18:33	1.7
+++ hp-symtab-read.c	2001/12/06 22:33:18
@@ -2018,6 +2018,9 @@ hpread_read_struct_type (dnttpointer hp_
   /* Clear the global saying what template we are in the middle of processing */
   current_template = NULL;
 
+  /* Fix up any cv-qualified versions of this type.  */
+  finish_cv_type (type);
+
   return type;
 }
 
Index: stabsread.c
===================================================================
RCS file: /cvs/src/src/gdb/stabsread.c,v
retrieving revision 1.16
diff -u -p -r1.16 stabsread.c
--- stabsread.c	2001/09/24 17:16:53	1.16
+++ stabsread.c	2001/12/06 22:33:19
@@ -4090,6 +4129,8 @@ read_struct_type (char **pp, struct type
       type = error_type (pp, objfile);
     }
 
+  /* Fix up any cv-qualified versions of this type.  */
+  finish_cv_type (type);
   do_cleanups (back_to);
   return (type);
 }